Automatic electrical signaling apparatus for railways.



R. P. BROUSSON. AUTOMATIC ELECTRICAL SIGNALING APPARATUS FOR RAILWAYSxAPPLICATION FILED A'PB..21,1911.

Patented Jan. 30, 1912 NTUR I W m ATTUHNZEYS 3 SHEETS-SHEET 1.

mm B) 4 wn WM WIT/{E5555 W7? R. P. BROUSSON. AUTOMATIC ELECTRICALSIGNALING APPARATUS FOR RAILWAYS. APPLICATION FILED APR.21,1911.

1,015,778, Patented Jan. 30, 1912.

3 SHEETS-SHEET 2.

W A 'ATTUH/VEKS' APPLICATION FILED APR.21,1911.

' Patented Jan. 30,1912.

3 SHEETS-$HBET 3.

FIG'E.

INI/E/YTUH A 770/?NEY5 ROBERT PERCY BLOCK SIGNALLING COMPANY, LIMITED OFLONDON, ENGLAND.

.BROIII'SSON', OF LONDON, ENGLAND, ASSIGNOR TO AUTOMATEG ELECTRICAUTOMATIC ELECTRICAL SIGNALING A PPARATUS FOR H-AELWAYS.

emme.

Specification of Letters Patent.

?aten.ted J an. 3t), 1912.

Application filed April 21, 1911: Serial No. 622,455.

To all whom it may concern:

Be it known that 1, ROBERT PERCY Bnousson, a subject of the King ofGreat Britain, and resident of 3 Highbury Place, I

England, electrical engineer, have 1nventedcertain new and usefulImprovements in Automatic Electrical Signaling Apparatus for Railways,of which the following is a specification. p

This invention relates toau'tomatic elec tric signaling for railwaysworked on the sectional block system with normally clear signalscommanding the entrace to electrically insulated track-sections, whereinthe switches for controlling the respective circuits through whichcurrent. is conveyed for maintaining the signals in the clear conditionare held normally closed, in opposition to gravity or spring pressure,.by means of solenoids whose energization is de: pendent upon that ofrelays 111 series, with the several track-circuits; the arrangementbeing such that on the one hand, the entrance of a train into anyparticular blocksection will bring about the interruption of the circuitof the solenoid which governs the switch appertainingto the signal attheentrance tosaid section, with the result that this signal will be put todanger and the solenoid-controlled switch will thereupon becomeautomatically locked in the corre sponding position, and that ontheother hand, the entrance of the train into a subsequent block-sectionand its final exit from the block-section first mentioned will bringabout the re-closure of the solenoid circuit, the electro-magneticrelease of the switchlock, and the consequent restoration of the signalto its normal or line clear condition.

been liable to cause considerable inconvenience 1n the trafiicarrangements. Thus, on.

the one hand, accidental failure of current in the circuit ofithesolenoid which governs London,

.to' be put to hence,

electro-magnet which co 'train) remaining locked at danger Thiselectro-magnetic release of the switch-lock at the proper moment iseffected" of an.:appropriate operative .latter passing into v manded bythe signal already referred to;

any one of the signal-controlling switches,

' will result in said switch, not only assuming, but also becominglocked in, the position wherein it causes the corresponding signaldanger i, so that thereafter, even if the supply of current be resumed,this signal will remain at danger and until the switch-lock has beenreleased, no train wili be able to pass the signal without specialprecautions being adopted On the other hand, on. passing into thetransmisof the to prevent accidents. failure of the vtrain,bloclcseotion in advance, to cause sion of current through the circuittrols the snitchlock (whether such failuri 36 due to accidental failureof currentsupply in said. circuit, or to faulty action on part of thetreadle-device operated by the train) will result in that signal (which.commands the entrance to the block-section in rear of the so that,assuming a supply of current to be available in the circuit of theelectro-magnet in question, it is necessary to despatch an other trainover the line, under special precautions, in order to bring about therelease of the switch-lock referred to and the res toration of thesignaling apparatus to normal condition. According to the presentinvention, which is designed to overcome these defects, means areprovided whereby, on'cessation of current in the winding of the solenoidwhich governs any signal-controlling switch, this switch, althoughpermitted to assume an intermediate position wherein the signal which itcontrols is put to danger, it will be there arrested by a ;stop wherebythe switch will be prevented -from passing to the final position whereinit becomes automatically looked as before until or unless certainconditionshave superv'ened. That is to say, the signal-controllingswitch will remain in the intermediate or unlocked position until, inthe ordinary course of working, a treadle-device (which may be thetreadle-devi'ce employed to efi'ect the release of the switch-lock atthe entrance of a block-section in rear of that commanded by the signalin question) has been brought into operation by the train on the theblock-section comthe result of the operation of this treadledevice beingto close the circuit of an elec- As a result of the presentimprovementfi in the event of the cessation of current in thesolenoid-winding bein due, not to the passage of a train intov t eblock-section commanded by the-signal to which such solenoid ap ertains,but to accidental and temporary ailure in the supply of current, therenewal of the current supply will at once and automatically bring aboutthe restora tion of the solenoid-controlled switch to normal positionand the consequent clearing of the signal. Furthermore, as thesolenoidcontrolled switch remains unlocked. when in the intermediateposition, subsequent I rent of low voltage) so as to attract its theentrance of the block-section in advance failure of the treadle-device,situated within of that occupied by the train, to effect the withdrawalof the switch-lock at the entrance of the section just vacated by thetrain, will not preventthe clearing of the signal in rear of the train;and hence such clearing will now' take place automatically so soon asthetra-in has finally left the section commanded by the signal.

In the accompanyin drawings,-Figure l is a diagram illustrating theinvention as applied to an underground or other electric railway whereinthe danger and line clear signalsrespectively consist of differ-v entlycolored lamps, and wherein the track rails are not used for theconveyance of the traction-current. Fig. 2 is a similar diagram whereinthe track rails are assumed to be used as traction-current conductors.Fig. 3 is" a detail view showing, in front elevation, thesolenoid-controlled switch for governing a signal, together with theparts more immediately associated with I the switch itself;

Referring first to Figs. 1 and 2, each block-section A of the track, twocomplete block-sections B and O, and part of another block-section D;the direction of the trafiic beingfrom left to right. Inasmuch as theapparatus used for the/several block-sections is of identically similarcharacter in all cases, correspondingparts or elements of the apparatusand connections, throughout all the sections, will be denoted (for thesake ofclearness) by similar reference symbols with the qualifyingaddition of the letter A, B, C or D appertaining to the particularsection which for the time being is in question. In Fig. 3, which showsseparately, a portion of the apparatus common to all the block-sections,the letters A, B, O, D, are omitted.

Referring now more particularly to Fig.

1, it will be seen that the one track-rail X- is continuous throughoutall the sections of the line, and serves, electrically, as a commonreturn' for the entire system, while the other rail is divided intoinsulated lengths YA, YB, Y0, and YD corresponding to the respectiveblock-sections. Electric power for working the signals is derived from acable'Z common to all the sections,

ed. through the windings of relays E,

whereof EB, EC and ED alone are shown. As usual, each relay is energized(by curtime the track-section to which the relay appert-ains is notoccupied by a train; whereas, on cessation of current, either throughfailure in the supply or in consequence of the winding beingshort-.circuited. as the result of the presence of a train F in thesection (as indicated in the case of section D), the rela becomesdee'nergized and its armature e fa ls. The several armatures e serveto'operate switches as at h controlling the supply of current. fromthecable Z to the windings 'of solenoids. G, whereof GB, GO and GD aloneare shown, one end of each solenoid-winding being connected to the cableZ through the corresponding armature-switch h, in such manner that onlyso long asthe corresponding. relay E is energized'will the connection beclosed, while the opposite end of the solenoid-winding is connecteddirectly to the common-return rail X. The entrances to the severalblock-sections of the line are governed by signals K, whereof KB, KC

and KD alone are'shown, each si nal comrisin a reen or safety signa -lamI [c End-a ed r danger signal-lamp he circuits of these lamps are ineach case con-' trolled by a multiple-switch operated by the core-stem gof the corresponding solenoid G; the stem carrying for this purpose twoconductive disks L and M. The core-stem 'g of each solenoid is-capableof occupying three positions. Of these" the raised or normal position(shown in the case of GB) wherein the disk-L closes at a air of con-. tacts l the power sideof the clrcuit of the green or safety lamp" [0 ofthe corresponding signal K, while the disk M closes at a pair ofcontacts m the return side of the same circuit, is maintained solely asa result Qf current passing in the-solenoid winding as heretofore. Inthe full lowered position (shown in the case of GO), wherein the disk Lcloses at a pair of contacts Z the power side of the circuit of thelower end of thestem g stem g is automatically locked by agravityoperated (or spring-pressed) latch a which then engages over thetop of the stem, and which is capable of being withdrawn from activeposition by means of an electro-magnet N as heretofore; the respectivelatches and the corresponding electro-magnets being shown at NB, NC, and

ing to the present invention the stem 9 is capable of occupying a thirdor. intermediate position (shown in the case of GD),

wherein the disks L and M close at Z and m respectively the power andreturn sides of the circuit of the red or danger lamp k as when in thefully lowered POSlhlOl'l;

this intermediate position being reached, however, before the stem 9 hasdescended so far as to become locked by the latch n. The intermediateposition is determined. by the encountering and resting upon a stop- 0,which is'norinally presented (by gravity or spring-pressure) in the pathof the stem, able of being withdrawn from such position by means of anelectro-magnet O; the respective stops and the correspondingelectro-magnetsbeing shown at OB, OO and OD. he circuit of eachelect-ro-magnet N is controlled by means of a third conductive disk Rcarried (in addition to the disksL and M) by the core-stem g of the"solenoid G apperta ning to the multiple-switch which controls the signalcommanding the entrance to the block-section in advance, this'disk B-being adapted to'close said circuit by bridging a pair of contacts r.The construction is such that the circuit in question remains broken atthe contacts 1' so long as the stem -g is in the highest andintermediate positions, as indicated in the case of the solenoids whensaid stem reaches as indicated in the case ofthe solenoid GC. Thecompletion of the circuit of each electro-magnet N is effected theaction of the train, upon the latter passing clear within theblock-section in advance; the train at the same time bringing about theclosure of the circuit of the electro-magnet O appertaining to. I themultipleswitch which controls t-lie 'signal command- 7, mg the entranceto said. advance section.

. For this purpoSeftre'adledevices 2 JB, JC and J D aloneareshown) areplaced alongside the track at points within the I'jentrances ofthe-respective block-sections as .rheretofo're, thesetradle-devicesbeing severa'lly adapted, in conjunction with theappropriate operativemember mounted on the rear of the .train, to admit current to thecircuits referred to. Inthe example illustrated in Fig.1, the traincarries at its rear ND. Accordand which is capsure line, ing pair v GBand GD respectively, and is closed at this point only thelowestposition,

(whereot ing stop 0 end a brush j which is to be understood asmaintaining permanent contact with the return-rail X through the mediumof the metallic frame, axle, and hind wheels oi the rear vehicle, thisbrushy' being adapted to establish connection with each ofthetreadle-contacts JB, J C and JD in succession. The cont-act J B isconnected to oneend of the winding of the electromagnet OB and also (inparallel therewith) to one of the correspondin pairs of contacts 1*, theother contact r of t is pair being: connected by a line-wire to one'endof the winding of theQelectro-magnet N appertaining to the solenoid(not'shown) at the entrance of the block-section A,- while theother endsof the winding of the .ame electro-magnet N and of the electro-magnet OBare connected to the power-cable Z. Similarly, the contact. J C isconnected to one end of the winding of the electro-rnagnet 0C and also(in parallel therewith) to oneot the corresponding pair of contacts 1',the other contact 1 of this pair being connected by a line-wire to oneend of the winding of the electromagnet NB, while'the other ends of thewindings of the electro-magnets 0C and NB are connected to the cable Z;and so on as indicated. It is to be observedthat the-treadle-contacts Jshould be made of sufficient length to inective transmission ofcurrent'in succession through those electro-magnets O and N which areconnected to the respective contacts J.

The normal working is as follows :-Assinning a train such as F to enterthe blocksection .B from the block-section .A of the the entrance intosection Bjof the lead of wheels f (which are as'sumed to be electricallyconnectefd through their axle) willcause the-relay EB to beshortcircuited, with the result that the circuit of the solenoid GB willbe broken at the switch hi?) and the core-stem 913 of this solenoid willdrop until arrested at theintermediate position by its stop 0, the fallof this stein g-causing current to be switched at L, M from the greenlamp k of the signal to the red lamp is? of the same signal. On thebrush j at the rear end of the train encountering the treadle-contactJB, the circuit of the electro-magnet OB will be completed andcurrent'will be'transmitted through the winding-of this electromagnet,with the result that the correspondwill be withdrawn and the stem gBallowed to fall to the lowest position. In this position the disk Rcarried by the stem gB bridges the corresponding pair or. contacts 1",with the result that current will now be transmitted through the windingof the electro-magnet N appertaining to the solenoid at the entrance .tothe block-section A, the efi'ectsof this being similar, as

regards said solencid, tothose about'to be described with reference tothe solenoid GB.

011 the brush j leaving the treadle-contact J'B, the electro-magnet OBwill cease to be energizedfland the correspondingstop will become freeto return to normal position when the core-stem 9B of the solenoid GB israised as hereafter described. After the train F has advanced so thatits leading pair of wheels f enter the block-section G, 10 theconditions already brought about as above described with reference tosection B Will continue so long as any pair of electrically connectedwheels of the train re main still within section B, the red lamp 115 70of the signal KB remaining lighted; but, the relay EC being nowshort-circuited by the presence of the train in section C, the solenoidGC will be deenergized and its core-stem 90 will drop to theintermediate position, with the result that, in the case of the signalK0, the green lamp 70 will be extinguished and the red lamp 70 lighted.On the last pair of wheels of the train passing out of the block-sectionB, the relay EB will cease to be short-circuited, and consequently thecircuit of the solenoid GB will be again closed at the switch hB. Since,however, the core-stem 9B of this solenoid is locked in the fullylowered position by its latch n, the connections'already established bythe disks L, M and R in the case of the solenoid GB will remainunaffected,

and the signal KB will still remain'at danger. On the brush j at therear end of the train encountering the treadle-contact J (l, theelectromagnet OC will become energized, and, thecorresponding stop 0being withdrawn from under the core-stem 9C,

this stem will drop to -.the lowest position,

40 with the result that, while the signal KC will remain at danger,"the'disk R carried by the stem gC will bridge the contacts '1' and theelectro-magnet NB will become energized. Hence, the stop 9?. controlledby this electro-magnet will be withdrawn, and, the solenoid GB stillremaining energized, the core-stem gB will be raised to the highestposition, with the result thatthe red lamp k ofthe signal KB will beextinguished and the green lamp k} of the same signal re-lighted. At thesame time the circuit controlled by the disk R carried by the stem gBwil be broken. On the brush'j leaving the tr'eadle-contact J C, theelectro-magnet OC will cease to be energized, and the corresponding stop0 will become free to return to normal position when the core-stem 9C isafterward raised.

Solong as a pair of wheels of the train remain in section'C, the signalKC will remain at danger but at the same time,

when the train has advanced so thatits leading pair of wheels entersection D, the rela ED will be short-circuited, the solelnoi GD will bedeenergize'd, and the corethe two signals to which the particular stem91) will drop, so that the green lamp of the signal KD willbeextinguished and the red lamp k of the same signal will be lighted. Onthe last pair of Wheels oij' the train passing out of section 0, therelay 70 EC will cease to be short-circuited, and the" solenoid GO willagain be energized, but its stem 90 will remain in the lowest position;this being the situation indicated in Fig. 1. The same sequence ofoperations will be repeated, during the progress of the train, everytime the latter passes from one blocksection of the line to another, aswill be readily understood. Let it now be assumed that an accidentalfailure of current takes so place in the circuit either of one of thetrack-relays E, or of one of the solenoids G. In either case thesolenoid immediately concerned will become deenergize'd, and itscore-stem 9 will drop so as to change the corresponding signal from lineclear to danger. The core-stem 9 will, however,- be arrested in theintermediate position by its stop 0, so that, as the corresponding latch11. will not have been permitted to come into operation to lock the stem9, the latter will be able to rise again to normal position, so

as to restore the corresponding signal to line-clear, immediately a flowof current recommences in the circuit wherein failure occurred. In theevent of a failure of current in the circuit of one of theelectromagnets O, the stop 0 which it controls will not be withdrawnfrom operative position when the corresponding treadle-device J isactuated. Hence the core-stem g of the corresponding solenoid will notdescend so as to become locked by its latch 02., but this fact will notaffect the condition of the signal governed by said core-stem, inasmuchas this signal will be put to danger on the entrance of' a train intothe block-section commanded by the signal, and will be returned to lineclear on the exit of the train from said section,-as usual. In the eventof failure on the part of the train to actuate one of thetreadle-devices J, or defective working in the device J itself, neitherof these will affect the condition ot treadle-device J ap ertains. Thatis to say, on the one hand, ailure of the tre'adle-device J to transmitcurrent through the winding of the corresponding electro-magnet 0 willmerely result in the sto 0 being left in operative posit-ion, with t eresult that the core-stem g of the corresponding solenoid will notdescend so as to becomelocked by its latch 11..- But the signalcontrolled by this solenoid will be put to den. ger and returned to lineclear on the en- I trance and exit of a train into and from theblock-section commanded by said signal, as

usual. On the other hand, the effect of the core-stern g (of thesolenoid referred to) 130 employed to conve only serve to ca v thetraclccircuit curbeing prevented from descending to its lowest positionby the non-w1thdrawal oii c I "ly to Fig. 2., it will be observed hearrangementi-einains the same as $1.. gust described with Referring nowi rdference to Fi 1 exec t re ards therails. That is to say, Whereas inFig. 1 (wherein the t-ra, 'i:;rails X Y are not 37 the traction currentbut rent) it rail Y i "it divided into insulated lc r i iding to therespecin 2 (wherein the traclcrai carry the traction our-. rent) thcontinuous, while a contact-rail tt ngside of and parallel to it so asxerve tor track-circuit purposes only, i is contact rail. being dividedinto insulatedlengths corresponding to the respective block-sections, asindicated in the case g A, 15, G and 3 1). in both arrangements thetrack-rail X serves as a common return for the entire electrical system.Since, in the arrangement illustrated in Fig. 2 the sectional rail 31A,g B, etc, does not carry the train wheels, the train is provided at eachend with a brush, as indicated at 3 adapted to contact constantly withsaid sectional rail; each brush y being in electrical connection withthe rail X through the frame, an axle, and the corresponding wheel ofthe first or lastvehicle of the train, as the case may be, so as tocause the presence of tie train in any block section A, B, etc, of theline to bring about the short-circuiting of the correspond track relayEA, EB, etc, so long as any part of the train remains within thesection.

It is unnecessary to describe the action of the apparatus with referenceto Fig. 2, as this is identical with that already described withreference to Fig. 1. In both arrangements, the dotted rectangles VB, VCand VB indicate the casings wherein are housed the solenoids G andn:ultiple-switches for controlling the signals which command theentrances to the block-s-ctions D, C and D of the line respccti Sindicate re is posed in the var .rus circuits.

Referring to F 1g. it will be seen that the pairs of contacts Z. F; m,m; and r, are all constituted by leaf-springs which normally extend in.a horizontal direction from their inc-es and T fuses interthe casinginclosing the solenoid G and the arts more immediately associatedtherewith, the free ends of the springs of the re spective pairs beingpresented in the paths of the corresponding disks L, M and R, which arefixed on the core-stem g but'insulaled therefrom and from each other. nand 0 are adjustable counterweights carried by the latch n and, stop 0respectively, these being constituted by the armature-levers ot therespective electro-magnets N and O. The weights n .and 0 serve tomaintain the latch n and stop 0 in normal or active position so long asthe resp-ctive armatures are not attracted in consequence of theenergization of the electro-magnets. In the highest position of the stemg, the disks L and Mrespectively bridge the spaces between 1 thefreeends of the pairs Z and m, while in the intermediate and lowestpositions of the stem, the respective disks bridge the spaces betweenthe free ends of the pairs Z an d of; the flexibility of the pairs ofsprings Z" and at being made suiiicient to permit of these springsbending so as to maintain contact with the respective disks L and M whenthe stem and disks descend by gravity so far below the intermediateposition to enable not only the disk R to bridge the space between thefree ends of thepair of springs 1*, but also the stem g to become lockedby the latch n. Y

Claims:

1. An electrically operated, automatically acting, block-signalingsystem for use on a railway line, consisting in the combination ofelectrical track-circuits corresponding respectively to the severalblock-sections of the line; electrically operated signals for commandingthe entrance to the respective block-sections; gravity-operated switchesfor controlling the circuits of the respective signals and capable ofoccupying three positions alternatively, namely, two extreme po sitionstherein the corresponding signals are put to line clear and dangerrespectively and an intermediate position wherein said signals danger;solenoids for retaining the respective signalcontrolling switches in theposition corresponding to line clear; electro-magnetic relays interposedin the respective track-circuits, and armatures therefor; switches,controlled by the respective relay-armatures, for normally closing thecircuits of the corresponding solenoids;-

are also put to for, for withdrawing the respective stops from operativeposition; means adapted to cooperate with a train on the latter passingwholly within the respective block-sections, for controlling thecircuits of the respective stop-withdrawing electro-magnets; andswitches, movable as one with the respective signal-controllingswitches, for closing the circuits of the respective latch-withdrawingstem 9; the solenoid G for holding said corestem in the extreme raisedposition; the latch n, and counterweight n for holding the same inposition to prevent the rise of the core-stem g in the'extreme loweredposition; the eleotro-magnet N for withdrawing the latch nfrom operativeposition; the stop 0, and counterweight o for holding the same inposition to arrest the fall of the core-stem gv at an intermediateposition the electromagnet O for withdrawing the latch o from operativeposition; the insulated conductive disks L,'M and R carried by thecore-stem g; the pairs of electrical spring contacts Z and m adapted tobe bridged 'by therespective disks L and M when in the fully contacts Zand m adapted to be bridged by the respective disks L and M when in boththe intermediate and the fully loweredpositions; and the pair ofelectrical spring contacts 1' adapted to be bridged by the disk B wheninthe' fully lowered position alone, substantially as described.

' ROBERT PERCY BROUSSON. Witnesses: 4 I p Y O. P. LIDDON,

H. D. JAMEBON.

. raised position; the pairs of electrical spring

